Traveling scaffold for bridges and the like



Feb. 16, 1954 1.8. KAUFMAN ,669 9 TRAVELING SCAFFOLD FOR BRIDGES AND THE LIKE 7 Filed Feb. 6, 1952 3 Sheets-Sheet l 259:1 1 VENTOR.

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TRAVELING SCAFFOLD FOR BRIDGES AND THE LIKE I Filed Feb. 6, 1952 5 Sheets-Sheet 2 .INVENTOR.

1954 I. s. KAUFMAN TRAVELING SCAFFOLD FOR BRIDGES AND THE LIKE Filed Feb. 6, 1952 3 Sheets-Sheet 3 INVENTOR. [Scale 3. ffa'ufmm Patented Feb. 16, 1954 TRAVELING SCAFFOLD FOR BRIDGES AND THE LIKE Isaac S. Kaufman, Mclrose Park, Pa., assignor to Kaufman Construction Company, Philadelphia, Pa., a corporation of Pennsylvania Application February 6, 1952, Serial No. 270,213

3 Claims. 1

The present invention relates generally to scaffolds and it relates more particularly to traveling scaffolds for use on bridges and like elevated structures.

An object of the present invention is to provide a new and useful scaffold construction. Another object of the present invention is to provide a novel traveling scaffold for use on bridges and like elevated structures. Still another object of the present invention is to provide an improved traveling bridge scaffold or the like, which is relatively simple and inexpensive to construct and which can be operated with ease and safety, so as to afford ready access to the underside of the bridge or like elevated structure, through-out the entire length thereof, and which can be readily manipulated so as to clear spaced supporting columns, cross-beams and other projecting obstructions. A further object of the present invention is to provide a traveling scaffold for bridges and th like elevated structures having a carriage adapted to rest upon and move easily along the roadway of the bridge; and having a cantilevertype platform adapted to be supported upon the carriage and to extend laterally outwardly therebeyond and inwardly in relatively close proximity to the underside of the roadway-supporting structure so as to give ready access thereto during construction and/or maintenance; and having means for swinging the platform outwardly so as to enable it to clear supporting columns, beams, trusses and other projections or obstructions and thereby to permit the scaffold to be moved along substantially the entire length of the bridge.

Other objects and advantages of the present invention are apparent in the following detailed description, appended claims, and accompanying drawings.

For the purpos of illustrating the invention, there are shown in the accompanying drawings forms thereof which are presently preferred and which have been found in practice to give satisfactory results. It is to be understood, however, that the invention is not limited to the precise arrangernents and instrumentalities shown, and that the several parts and elements can be variously arranged and organized, without departing from the spirit or essential attributes of the invention.

Referring to the accompanying drawings in which like reference characters indicate like parts throughout:

Figure 1 is a perspective view showing the travcling scaffold as it appears in use during the construction of a bridge.

Figure 2 is a vertical cross-sectional view gen erally along the line 22 of Fig. 1.

Figure 3 is an enlarged fragmentary perspective view of the platform portion of the embodiment of Figs. 1 and 2.

Figure 4 is a top plan view of the embodiment of Figs. 1-3, portions of the bridge roadway being broken away better to reveal the construction of the scaffold.

Figure 5 is a fragmentary vertical cross-sectional view generally along the line 5-5 of Fig. 4.

Figur 6 is a fragmentary vertical crosssectional view generally along the line 66 of Fig. 4.

In Figs. 1-6, there is shown one embodiment of the present invention, which includes a carriage, indicated generally by the reference character ill, comprising longitudinally-extending side chassis or frame members II and 12 (each made up of a pair of superimposed I-beams, as best shown in Fig. 2), and transversely-extending end chassis or frame members I3 and I4, fastened to the underside of the members II and i2, and carrying, at their ends, axles l5, upon which are mounted four wheels iii. For purposes of illustration, the traveling scaffold of the present invention is shown in use during construction of a bridge, which is indicated, schematically, as made up of a plurality of spaced trestles, each having a base or foundation (not shown), a pair of vertical, transversely-spaced columns A, and a cross-beam B, connecting the upper ends of the columns A and extending outward somewhat therebeyond. Resting upon, and supported by, the cross-beams B, are a plurality of longitudinally-extending, transversely-spaced I-beams C, which in turn support a roadway D of newly poured reinforced concrete, having side curbs E. The wheels it of the carriage Ill rest upon, and are adapted to roll along, the roadway D, with the wheels on one side adjacent one of the curbs E, as shown in Figs. 2, 4 and 5.

Mounted on top of the chassis members I I and I2, are a pair of transversely-extending U-beams l1 and 3, which protrude laterally somewhat beyond the wheels l6. Extending along the inner ends (1. e. the ends farther from the curb E) is a longitudinal platform [9 carrying, adjacent one end thereof, a Windlass 20.

An underhung cantilever-type platform-member, indicated generally by the reference character 2|, is pivotally mounted on, and supported by, the carriage ID in a manner to be described below.

Th P atform-member 2| includes a pair of spaced, normally horizontal, uppermost structural members 22 and 23, the inner ends of which are disposed in overlapping, side-by-side relationship to the outer ends of the U-beams, while the outer ends of the members 22 and 23 extend substantially beyond the edge of the roadway D. Connecting members '24 and 25 ar welded or other.- wise suitably secured to the upper edges of the structural members 22 and 23 and serve rigidly to interconnect the inner and outer ends respectively of said structural members.

The innermost ends of the structural members 22 and 23 are provided with right-angular extensions 26 and 21 respectively, which normally extend vertically downwardly therefrom, as shown in solid lines in Fig. 2, in juxtaposed relation to generally similar downward extensions 28 and 29 secured to the U-beams ill and I8 somewhat inside the chassis member :2. The extensions 26 and 21 are pivotally connected to the extensions 28 and 29 by pivot pins 22 and 2| passing through aligned holes formed therein adjacent the lower ends thereof; the pivot pins being disposed below the level of the chassis members ['3 and M, as shown in Fig. 2.

Removable locking-pins 4.3 and .41 are adapted to be fitted into aligned holes in the U-beams l1 and H3 (near the outer ends thereof) and the structural members 22 and 23, so as to lock the latter to the uebeams in horizontal position, with the lower edges of the structural members 22 and 23 resting upon the top of the chassis member 12, as shown in Figs. 2 and 4.

The outermost ends of the top structural members 22 and 23 are rigidly secured to the outermost ends of the lowermost, normally horizontal, inwardly extending structural members 32 and 33 of the platform member 2 l, by normally vertically disposed perpendicular side members 34 and 35 and crossing diagonal members 36 and 31. Downwardly and inwardly inclined side rails 38 and 39 extend from the structural members 34 and 35 to the inner ends of the lowermost structural members 32 and 33, which terminate generally at the center line of the roadway D, the rails relatively closely clearing the bottoms of the I-beams C when in the normal workin position shown in solid lines in Fig. 2, but being above the level of the bottoms of the cross-beams B.

Suitable struts or bracing members 48 connect the members 223234, while similar struts 4| connect the members 2333-35 to provide a rigid cantilever-type construction for the platform-member 2|. members 42 and 43 similarly connect the members 32-38 and 3339 respectively, as shown in Figs. 1, 2 and 3.

As indicated particularly in Figs. 1 and 3, beams 44 extend intermediate the lowermost structural members 32 and 33 of the platforin-member 2!, and provide support for flooring panels 45, upon which workmen or inspectors can stand for safe sive access to the underside of the bridge struc- W as t fa il t nstallsf i e 9 rem s1; of

Suitable struts or bracing temporary deck-forms for the concrete roadway, by way of illustration.

However, to permit the scaffold to pass beyond trestles and thereby to enable it to be used on successive spans of the bridge or the like, I provide means for shifting the platform-member 2|, from its normal working position, shown in solid lines in Fig. 2, to the position shown in dash-dot lines in Fig. 2, wherein the structural members 22 and 23 extend vertically upwardly, the members 34?3536-31 extend horizontally outwardly beyond the roadway, and the members 32-33 and 38-39 extend downward laterally beyond the trestle, so as to enable the platformmember to clear the vertical column A and the cross-beam B, while the carriage is being moved (for example, from left to right in Fig. 1).

The aforesaid shifting means comprises a flexible cable or rope 48, secured at one end to a projection 49 on the top of the chassis member H, and passing over pulleys 5i] and 5| hooked to .apertured anchorage-members 52 and 53 fastened to the upper side of the connecting member 25 adjacent the ends thereof; the other end of the cable or rope 48 being wrapped around the drum of the Windlass, so that, after the locking-pins 46 and 41 have been removed from the locking position shown in Fig. 6, operation of the Windlass handle will shorten the effective length of the cable .or rope. and, in so doing, will shift the platfrom-member -2| from the solid.- line working position of Fig. 2 to the dash-dot trestle-bypassing position of Fig. 2.

After the trestle has been cleared, the windlass handle is oppositely rotated to lower the platform-member back to its normal working position, after which the locking-pins are reinserted and the workmen (who, of course, had left the platform prior to its being up-ended') return to the platform-member to begin work on the next span of the bridge or viaduct.

The carriage and platform-member are so proportioned and the weight thereof so distributed that the center of gravity of the scaffold is always inside of the outer wheels, whether the platform-member is in the normal working position or the up-ended trestle-clearing position, so that there is never any tendency for the carriage to tilt (clockwise in Fig. 2) sideways and upset.

If desired, a pair of scafiolds can be mounted, one at each edge of the roadway, so that the platforms thereof terminate adjacent each other at the center of the underside of the bridge and thereby give access to the entire width of the bridge underside at the same time, the two carriages being moved simultaneously. In this ar.- ran ement, the carriages and/or the inner ends of the lowermost structural members can be rigdly in erc nn c ed o en re ynchron mov me OI" he wo scafio ds- Of course, the relative proportions of the scaffold can be varied to adapt it to particular installations and uses. By way of illustration, the vertical clearance of the top structural members 22 and 23 could be increased to allow for guard rails on the roadway, such as would. be installed on a completed bridge or viaduct, while the lower portion of the platform-member could be lowered to give greater clearance beneath the v I-beams to facilitate movement along the flooraccess to the underside of elevated structures so as greatly to reduce the time and hazard involved in construction, inspection, maintenance and repair thereof. It is also obvious that, after a job at one site has been completed, the scaffold can be readily disassembled into its carriage and platform components, simply by removal of the pivot-pins, to facilitate transportation to, and reassembly at, a new site.

The present invention may be embodied in other specific forms and, accordingly, the foregoing embodiments are to be considered merely as illustrative, and not restrictive, reference be ing made to the appended claims, rather than to the above specification, as indicative of the scope of the invention.

I claim as my invention and desire to protect by Letters Patent, the following:

1. A traveling scaffold for a bridge 0): like elevated structure, including a carriage constructed and arranged to rest on and move along an upper surface of said bridge generally adjacent one edge thereof, said carriage having a chassis and a plurality of wheels mounted on either side thereof, and a cantilever-type platform-member supported from said carriage, said platform-member having structural-means constructed and arranged to extend generally horizontally outwardly from said carriage beyond the adjacent edge of the bridge, and having structural-means constructed and arranged to extend downwardly from the outer end of the first-mentioned structural-means, and having structural-means constructed and arranged to extend generally horizontally inwardly from the lower end of the second-mentioned structuralmeans to a point substantially beyond the inner side of the carriage, said last-mentioned structural-means including a working platform disposed relatively adjacent the underside of the aforesaid upper surface and roviding access to said underside, the center of gravity of the scaffold falling in a plane laterally intermediate the sides of the chassis so that there is no tendency for the carriage to tip over sideways when in use, the platform-member being pivotally connected to the chassis with the axis of pivotation laterally intermediate the sides of the chassis and somewhat below the wheel axes, the platformmember being tiltable through approximately degrees so as to position its last-mentioned structural-means in downwardly-extending generally vertical position outside the adjacent edge of the bridge so as to enable the platformmember to clear underlying bridge projections during movement of the carriage, the center of gravity of the scafiold in up-tilted position still falling in a plane laterally intermediate the sides of the chassis.

2. A construction according to claim 1 wherein the scaifold includes means for mechanically raising and lowering the pivotally-mounted platform-member to and from its up-tilted position, and means for locking the platform-member selectively in either its raised position or its lowered position.

3. A construction according to claim 2 wherein the raising and lowering means comprises a windlass mounted adjacent the inner edge of the carriage chassis and constructed and arranged to actuate the platform-member through a cableand-pulley system operatively connected to the first-mentioned structural means adjacent the outer end thereof.

ISAAC S. KAUFMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,427,453 Fleming Aug. 29, 1922 1,442,697 Orthmann Jan. 16, 1923 2,598,730 Thompson et a1 June 3, 1952 2,639,950 Wheeler May 26, 1953 

